var activity int32
	rwm := NewLRWMutex()
	cdone := make(chan bool)
	go writer(rwm, numIterations, &activity, cdone)
	var i int
	for i = 0; i < numReaders/2; i++ {
		go reader(rwm, numIterations, &activity, cdone)
	}
	go writer(rwm, numIterations, &activity, cdone)
	for ; i < numReaders; i++ {
		go reader(rwm, numIterations, &activity, cdone)
	}
	// Wait for the 2 writers and all readers to finish.

		var activity int32
		cdone := make(chan bool)
		go writer(resource, numIterations, &activity, cdone)
		var i int
		for i = 0; i < numReaders/2; i++ {
			go reader(resource, numIterations, &activity, cdone)
		}
		go writer(resource, numIterations, &activity, cdone)
		for ; i < numReaders; i++ {
			go reader(resource, numIterations, &activity, cdone)
		}

		t.Fatal("Unlock timed out, which should not happen")
	case <-timer.C:
	}
}

// Borrowed from mutex_test.go
func HammerMutex(m *DRWMutex, loops int, cdone chan bool) {
	for range loops {
		m.Lock(id, source)
		m.Unlock(context.Background())
	}
	cdone <- true
}

// Borrowed from mutex_test.go
func TestMutex(t *testing.T) {
	loops := 200
	if testing.Short() {
		loops = 5
	}

						rs.LastSaved = UTCNow()
						sm.peerResyncMap[dID] = rs
						wg.Add(1)
						go func() {
							defer wg.Done()
							saveSiteResyncMetadata(ctx, st, newObjectLayerFn())
						}()
					}
				}
				wg.Wait()
				sm.Unlock()
			}
			sTimer.Reset(siteResyncSaveInterval)
		case <-ctx.Done():
			return
		}
	}
}

// update overall site resync state

	return hashPath(d.Info.Name)
}

// clone returns a copy of the cache with no references to the existing.
func (d *dataUsageCache) clone() dataUsageCache {
	clone := dataUsageCache{
		Info:  d.Info,
		Cache: make(map[string]dataUsageEntry, len(d.Cache)),
	}
	for k, v := range d.Cache {
		clone.Cache[k] = v.clone()
	}
	return clone
}

// merge root of other into d.

		t := time.NewTicker(updateTime)
		defer t.Stop()
		defer saverWg.Done()
		var lastSave time.Time

		for {
			select {
			case <-t.C:
				if cache.Info.LastUpdate.Equal(lastSave) {
					continue
				}
				scannerLogOnceIf(ctx, cache.save(ctx, er, dataUsageCacheName), "nsscanner-cache-update")
				updates <- cache.clone()

				lastSave = cache.Info.LastUpdate
			case v, ok := <-bucketResults:

	list.totalEvents.Add(1)
}

func (list *TargetList) sendAsync(event Event, targetIDset TargetIDSet) {
	select {
	case list.queue <- asyncEvent{
		ev:        event,
		targetSet: targetIDset.Clone(),
	}:
	case <-list.ctx.Done():
		list.eventsSkipped.Add(int64(len(list.queue)))
		return
	default:
		list.eventsSkipped.Add(1)

	httpServer := newHTTPServerFn()
	if httpServer == nil {
		return 0
	}

	return httpServer.GetRequestCount() - activeListeners()
}

func waitForLowHTTPReq() {
	maxIO, maxWait, _ := globalHealConfig.Clone()
	waitForLowIO(maxIO, maxWait, currentHTTPIO)
}

func initBackgroundHealing(ctx context.Context, objAPI ObjectLayer) {
	bgSeq := newBgHealSequence()
	// Run the background healer

	for dID, v := range sr.M {
		t := newXferStats()
		mx := make(map[RMetricName]XferStats)

		if v.XferRateLrg != nil {
			mx[Large] = *v.XferRateLrg.Clone()
			m := t.merge(*v.XferRateLrg)
			t = &m
		}
		if v.XferRateSml != nil {
			mx[Small] = *v.XferRateSml.Clone()
			m := t.merge(*v.XferRateSml)
			t = &m
		}

		mx[Total] = *t
		metric := SRMetric{
			ReplicatedSize:  v.ReplicatedSize,

		// replicate only if lifecycle rules are not applied.
		done := globalScannerMetrics.time(scannerMetricCheckReplication)
		i.healReplication(ctx, oi.Clone(), sizeS)
		done()
		return size
	}

	vc, err := globalBucketVersioningSys.Get(i.bucket)
	if err != nil {
		scannerLogOnceIf(ctx, err, i.bucket)
		return
	}

	// start ILM check timer
	done := globalScannerMetrics.timeN(scannerMetricILM)